1. Field of the Invention
The present invention is generally related to optical switches and, more particularly, to an optical switch which is provided with a tamper indicating feature that recognizes the existence of light received by the optical switch from an external light source.
2. Description of the Prior Art
In many different types of applications, it is necessary to count objects as they move past a predetermined location. For example, in certain document counting systems, a light source and a light sensitive component are arranged to define a detection zone therebetween. As objects pass between the light source and the light sensitive component, the light path between these devices is obstructed. The obstructions can be counted so that the number of objects passing along a preselected path can be determined.
One particular application of this type of apparatus is in a gambling device such as a slot machine. Gambling devices of this type are typically provided with an automatic means for dispensing coins to a player as winnings. Optical switches permit the rapid dispensing of coins while also providing signals that can be counted as the coins are dispensed to the winning player. Although optical switches can be used in many different types of applications, the provision of a tamper detection capability in association with an optical switch is particularly important when the switch is employed in a device such as a slot machine where the effect of successful tampering can be extremely costly.
Several systems have been developed in recent years to LO prevent the successful tampering with optical switches in gambling devices. These prior art systems are described below in conjunction with FIGS. 2, 3 and 4.